<?php

$Menu = new Menu();
$navigation = new Zend_Navigation($Menu->formNavHierarchy($Menu->buildHierarchy()));
$this->navigation($navigation);
//echo $this->navigation()
//          ->sitemap()
//          ->setFormatOutput(true)
//          ->setRole(); 
$this->navigation()->sitemap()->setFormatOutput(true); 
echo $this->navigation()->sitemap();